By Jeffrey Krauss, Standards Subliminator and President of Telecommunications and Technology Policy

More and more, the cable industry is using technology based on published standards, rather than proprietary technologies. The Society of Cable Telecommunica-tions Engineers (SCTE) is the cable industry's own standards body. The SCTE has had notable success in several areas. One standards subcommittee adopted the DOCSIS cable modem standards. Another one adopted all the important standards for digital television, including video coding, transport specifications, and interface standards.

SCTE employees don't invent the technology or write the standards; that's done by the members. Members include cable equipment vendors, consumer electronics manufacturers, cable programmers and MSOs. CableLabs plays a key role by funding the research that leads to technology development, and then funding the documentation of the specifications. CableLabs specifications are usually submitted to the SCTE for adoption as standards in an open review process.

The SCTE standards program provides a key strategic tool for the cable industry. Once, cable standards were written by the consumer electronics manufacturers and broadcasters. Indeed, many of those standards continue to be used by the cable industry. But now the cable industry has its own ability to specify, for example, what behavior by subscriber-owned equipment would cause "harm to the network" and should be prohibited.

One important cable standard, the cable channel plan, belongs to the Consumer Electronics Association (CEA) because it was writing cable standards before SCTE existed. And indeed, CEA documented the three channel plans used by the cable industry because cable-ready analog TV sets needed to know the precise frequencies. CEA also wrote the standards for both analog and digital closed captioning, and for the digital TV use of the computer industry interfaces known as IEEE 1394 and DVI.

There has been tension between SCTE and CEA standards activities, because they overlap at the interface between the network drop cable and the receiver or set-top box. This interface determines the definition of a "digital cable-ready" receiver. Indeed, there is a CEA standard today, CEA-818, that purports to specify not only the receiver side of the interface but also the network side. It largely references the relevant SCTE standard, but not entirely–there are some differences. A few years ago, in a classic turf battle, CEA opposed SCTE's entry into the cable standards arena, on the grounds that CEA was already writing cable standards. CEA lost that fight, but the tension over what constitutes a "digital cable-ready" TV receiver, and who gets to document that specification, continues.

The Advanced Television Systems Committee (ATSC) develops and adopts standards for broadcast television. At the FCC's request, ATSC documented the U.S. broadcast digital television standard. Lately, ATSC has adopted standards for carrying program and system information (PSIP) in the digital TV signal, and for future applications like data broadcasting and an interactive application platform. ATSC has tried, so far unsuccessfully, to get the FCC to adopt its PSIP standard as a mandatory requirement for broadcasters.

ATSC is dominated by broadcasters and has very little participation by the cable industry, but nonetheless, has some standards that cover cable industry practices. While these existing standards generally reflect current practices, there is no mistaking the competitive tensions between cable operators and broadcasters. In the standards arena, the tensions center around FCC must-carry rules. Cable is allowed to strip out some elements of a broadcaster's signal, but broadcasters don't want the standards to make it easy. Also, there are technical differences between the hostile broadcast propagation environment compared with the friendly cable environment that lead to differences in standards. So cable can use a more complex 256-QAM modulation method that packs 38 Mbps into 6 MHz, while broadcasters are limited to 19 Mbps using 8-VSB modulation. And finally, cable has an out-of-band channel to carry program and system information, and so does not need to employ the broadcasters' PSIP standard.

But in spite of competitive tensions and technical and architectural differences, and in spite of the tendency of standards to retard technological innovation, harmonized standards do result in economies of scale. A harmonized cable/broadcast standard for an interactive application platform is being negotiated, to replace the separate standards that cable and broadcast developed. Also, following the path of the cable modem standards, set-top box specifications developed by CableLabs are evolving into SCTE standards for portability, so that a subscriber can move a set-top box from one cable system to another and it will work. These initiatives will lead to economies of scale in subscriber equipment. On the other hand, cable is deeply committed to QAM modulation, and broadcast is deeply committed to VSB. But in this case, it is possible to manufacture tuners that decode both, at little or no additional cost. And standards will continue to play a strategic role in the broadcast-cable competitive environment, leveraging the advantage of cable's vastly greater spectrum capacity.

Have a comment? Contact Jeff via e-mail at: jkrauss@cpcug.org